1. Field of the Invention
The present invention relates generally to optical image scanners and more particularly to flatbed scanners.
2. Description of the Related Art
There are currently available flatbed scanners comprising translatable object-imaging devices incorporating contact image sensors for detecting or capturing a scanned image. A contact image sensor is inherently more compact than a charge coupled-device (CCD) which, unlike a contact image sensor, requires image reduction optics. On the other hand, a contact image sensor produces lower quality images and has almost no depth of field, being unable to sharply image objects that are more than a few millimeters above the scanner platen.
Accordingly, it has been recognized that it is desirable to employ CCD technology in a flatbed scanner to gain the image quality and depth of field capabilities of that technology while at the same time reducing the footprint of such a scanner. One way to reduce the scanner footprint is to reduce the length of the document window through which the document is scanned. Reduction of the window length, however, may limit the usefulness of the scanner to scanning relatively small objects such as photographs. To increase the utility of the scanner so that it can handle, for example, letter size and legal size documents, additional equipment, such as an automatic document feeder, may be added to the scanner.